It would be nice to be able to access the website on a smartphone (even if the experience is suboptimal), instead of denying access.
Manhattanhenge is cool but people standing in the middle of street for it is pretty nuts.
It would be good to also have the option for alignment with sunrises in addition to sunsets.
For instance in Houston the sunrise aligns with Texas Avenue around the June solstice.
Consequently, there are no sunset alignments for the downtown skyscrapers.
Interesting, I've planned similar shots before and used different tools that serve a similar purpose. The Photographer’s Ephemeris has nice visualizations: https://photoephemeris.com/
NASA's Horizons ephemeris is also pretty good at preparing data for this. I've used it with a little script to check when the sun/moon will be in a given box. This hengefinder looks neat and really streamlined for its purpose though.